Puffing gun indexing mechanism



May 21,1957 LONG r L I 2,792,772

PUFFING GUN INDEXING MECHANISM 3 Sheds-Sheet 1 Filed Jan. 3, 1956 INVENTORS' GEORGE LONG YSTflA/LEY C. EUSTflD B 7%CW HTTORNE'S/ y 1, 1957 G. LONG ETAL PUFFING GUN INDEXING MECHANISM 3 Sheets-Sheet 2 Filed Jan. 3,1956

FIG. 4

w 6 m F w m FR INVENTORS' ae'oeqs LONG STANLEY C. 05700 W 21, 1957 G. LONG ETAL 2,792,772

PUFFING GUN INDEXING MECHANISM Filed Jan. 3, 1956 s Sheets-Sheet s 1/ me I76 g1 ma /ao r- V INVENTdRS 82 qeoe'qs LONG 111 BYSTENLNEY a. eusrno H 7'7'ORME V PUFFING GUN INDEXING MECHANESM George Long and Stanley C. Rustad, Minneapolis, Minn.,

assignors to General Mills, Inc., a corporation of Delaware Application January 3, 1956, Serial No. 557,072

10 Claims. (Cl. 99-238) This invention relates to pulfing guns and more particularly to an improved indexing mechanism for such guns.

Putting guns are known in the prior art in which a gun barrel is suitably mounted for rotation. In some cases it is important to be able to stop this rotation at a specific predetermined angular position. While it is possible to stop the rotation of such a gun at random, and then inch the gun into the desired angular position, such method of operation is time-consuming and requires the careful attention of an operator.

Some attempts have accordingly been made to provide a mechanical stop which would arrest the rotation of the gun barrel at the desired point. Because of the mass and the kinetic energy of the rotating parts, it is desirable that they be substantially at rest before they are firmly locked in position. Prior devices have attempted to achieve this objective by switch controls, which terminate the application of rotary power to the barrel a predetermined angular distance before the latching point is reached. Such an arrangement is not, however, readily adaptable to normal operations because it requires substantial readjustment in case different operating speeds for the barrel are desired. The device may also function inefiectively in case of variations in the frictional resistance of the parts to rotation, i. e. under varying temperature conditions.

With these problems of the prior art in view it is accordingly one object of the present invention to provide an improved indexing means for a puffing gun assembly.

A further object is the provision of an indexing mechanism which insures proper absorption of the rotational energy of the assembly.

Still another object is a pufling gun indexing mechanism which will operate satisfactorily over a wide range of conditions.

Another object is such an indexing mechanism in which adjustment of the final locking position can be readily made.

Other objects and advantages will be apparent from the following specification in which certain preferred embodirnents of the invention are described in the drawings which form a part of this application.

Figure 1 is a side elevation of a pufiing gun assembly incorporating features of the present invention, with certain portions broken away for clearness;

Fig. 2 is a view taken from the rear of the device of Fig. 1 along the line indicated at 2-2 and with certain portions broken away for clearness;

Fig. 3 is an enlarged partial view of the parts of Fig. 2 showing details of the locking latch mechanism in releasing position;

Fig. 4 is a sectional view on the line 44 of Fig. 3;

Fig. 5 is a sectional view on the line 55 of Fig. 3;

Fig. 6 is a view similar to Fig. 3 showing the parts in position after the latching mechanism has been released States Patent 0 2,792,772 Patented May 21, 1957 for movement to locking position, but before the parts are fully locked;

Fig. 7 is a view similar to Fig. 6 showing the parts in locked position;

Fig. 8 is a view similar to Figs. 2 and 3 showing a preferred embodiment of the invention; and

Fig. 9 is a partial sectional view on the line 99 of Fig. 8.

As shown in Fig. l, the present invention is adapted for use in connection with a puffing gun assembly of known construction. Such a puffing gun is described, for example, in Hayden Patent 2,279,868, assigned to General Mills, Inc. Reference may be made to this patent for disclosure of details of the pufling gun assembly which are helpful, but not essential, to an understanding of the present invention.

The puffing gun includes a frame indicated generally at 10. This frame may include a stationary base portion 12 and a movable frame portion 14 pivoted at 16 to suitable pedestals 18 on the base. Thus the frame includes both stationary and movable members adapted to tilt the axis of the puffing gun to the desired positions for loading, cooking, and discharge.

The pufling gun further includes a gun barrel assembly mounted on the frame portion 14 for rotation during cooking. The gun barrel assembly includes a barrel portion 20 and a removable cover 22 at one end of the barrel. A cover-supporting arm 24 is pivoted at as to one side of the barrel.

A locking link 28 is pivoted to a latch lever 30, which is pivotally mounted at 32 on the opposite side of the barrel. The latch 39 may be swung on its pivot between the locking position shown in heavy lines in Fig. l and a downwardly displaced releasing position. Thus a releasable locking means is provided securing the cover to the barrel and this locking means rotates with the barrel during operation.

When the cooking operation is complete and the barrel is to be opened, it is adapted for rotation to a predetermined angular position in which the lever 30 is in the position of Fig. l. The entire gun barrel assembly and frame 14 may then be tilted about pivot 16 to move the releasing projection 34 of the cover-locking means into the dotted line position of Fig. 1. At this point a suitable releasing means, including a tripping or firing lever 36 is swung from the heavy line to the dotted line position of Fig 1, so that a projection 38 on this arm engages above the projection 34 of the cover-locking means. This swinging movement may be accomplished through lever arm 40 link 42 and a lever 44 which includes a foot pedal portion 46 and a return spring 48. With the parts in the dotted line position in Fig. 1, it is then only necessary to swing the frame 14 and gun barrel assembly back toward the horizontal position around pivot 16. The locking lever 39 will be retained by the projection 3? and locking link 28 will thus be swung and disengaged from the cover-support arm 24 to permit that arm and its cover to move forcibly outward and upward.

Suitable shock-absorbing means may be provided in the form of a buffer at 50 for engagement by the cover or cover-carrying arm. The shock-absorbing means may include a cylinder assembly 52. Since the details of the shock-absorbing mechanism form no part of the present invention, they will not further be described. Certain portions of the shock-absorbing arrangement shown in Fig. l are, however, described and claimed in the co-pending application of Long and Tsuchiya, Serial No. 557,073, filed of even date herewith and assigned to the same assignee as the present application.

To provide for rotation of the gun barrel 20 during operation a suitable motor 54 is carried by the movable frame 14. This drive motor is connected by suitable pulleys and belt to rotate a cross shaft 56. Cross shaft 56 in turn carries a worm gear 58 (Fig. 2) adapted to rotate the main gear 60 which is keyed at 62 (Fig. 3) to the shaft 64 which establishes the axis of rotation of the barrel 20. Bari-e120 is secured to shaft'64 for rotation with shaft 64 and gear 60.

Secured to gear 60 is an indexing ring 66 to which is secured an indexing stop 68. The stop member 68 includes a radial surface 70 adapted to be engaged by the end 72 of an indexing latch member 73 which is pivoted at 74 on a latch support plate or member 76. The latchsupporting member 76 is rigidly secured to a hub portion 78, which is freely rotatable on a suitable bushing 80 carried by the hub 82 of gear 60. Thus the latch support 76 is mounted for rotation coaxially with the gun barrel assembly. This mounting provides for limited movement of the latch with the gun barrel assembly during the stopping and indexing operation as described below.

The latch 73 is movable between locking and releasing positions with respect to the surface 70. A lever 84, operatively associated with the latch member is connected locked parts from this heavy line position to the dotted line position of Fig. 2. Once the limited movement has been arrested, the spring 110 will contract and will rotate the parts back to the heavy line position of Fig. 2 so that the cover-locking members will be in the desired angular position. 7

Because the mass and kinetic energy of the rotating gun barrel assembly may be substantial, additional shockabsorbing means are provided. Here the additional means include a piston and cylinder assembly, including a piston rod 116, secured at 108 to the latch support. A piston 118 on the end of rod 116 slides within a shockabsorber cylinder 120, one end of which may be pivoted at 86 to a spring 88, the other end of which is secured at ing stop 68, when the gun barrel assembly rotates into the position of Figs. 3 and 7. A lifting hook 92 is secured to the end of the locking lever to hold it upwardly against the action of spring 88 in the manner described below.

Pivoted at 94 to the latch-support plate 76 is another index latching member or lever 96 having a locking end 98 adapted to engage the opposite radial surface 100 of the indexing stop 68. The lever arm 102 rigidly associated with latch member 96 is connected to one end of the spring 106. The other end of the spring is secured at 104 to the latch-support plate 76. Spring 106 urges the latch member 96 in a clockwise direction in Fig. 3 and thus tends to move the locking projection 98 into engaging or locking position behind the surface 100 of indexmg stop 68, as shown in Fig. 7.

As indicated by the foregoing description, the latching portlons 72 and 98 will tend to engage the indexing lug 68 when they are in their lower or locking position under the influence of the respective springs. In that position, as shown in Fig. 7, the latch members and latch supports 76 Wlll be eifectively locked to the gun barrel assembly to prevent relative rotation between these parts. On the other hand, when the latching portions 72 and 98 are lift ed to the releasing position of Fig. 3, the gun barrel assembly will be free to rotate without restraint from the latch members or latch support.

According to an important feature of the present invention, the latch-support member is operatively associated with shock-absorbing means adapted to permit, but reslst with increasing force, some limited additional angular rotation of the gun barrel assembly after the latching members have engaged the indexing stop. The extent of this relative rotation or limited additional movement is indicated in Fig. 2. Here the heavy line position is the normal one in which the gun barrel assembly is to be held in the predetermined angular position shown in Fig. 1, while the cover is unlocked. The dotted line position of Fig. 2 shows the maximum limited movement of the latchsupport member as the parts are brought to a stop.

The shock-absorbing means according to the present invention may be secured at 108 to the latch-support unit 76 and may include a spring member 110, the other end of which is connected at 112 to a bracket 114 on the frame 14. Spring 110 is connected under tension and its resistance to further stretching will provide a gradually increasing shock-absorbing action, after the latch members engage and lock the gun barrel assembly in the heavy line position of Fig. 2 and during movement of the at 122 to a bracket 124 onframe 14. The piston and cylinder shock-absorbing assembly may be of any desired construction adapted to provide a gradually increasing cushioning resistance against movement of the parts from the heavy line to the dotted line position of Fig. 2.

As the parts come to a stop, spring urges them back to the desired predetermined angular position. Adjustable stop means are provided to locate this position with accuracy. Thus the latch support member includes a stop surface 126 (Fig. 2) adapted to engage an adjustable stop 128 which may be provided as an adjustable bolt threaded into a frame portion 130. A locking nut 132 may be loosened to permit adjustment of the relative angular position of the stop and then tightened to retain the parts in their adjusted position. This adjustable stop provides means for accurately determining the locked pos'ition of the parts and thus accurately positioning the locked assembly so that the desired further operations can take place. This arrangement also provides a convenient adjustment to make necessary corrections for wear of the parts, since the stop can be readjusted whenever it appears that the gun barrel assembly is no longer stopping in the exact desired position.

As indicated above, the indexing latch 73 includes a hook portion 92 adapted to control the position of the latch. A similar hook portion 134 is provided on latch 96. It will be understood that latch 73 acts as the stop which prevents further rotation of the gun barrel assembly in the normal operating direction of the arrows, except to the limited extent permitted by the rotation of the latch-support plate and the shock-absorber units. Latch member 96, on the other hand, prevents any rebound of the index stop 68 from latch 72 and limits the return rotation of the gun barrel assembly to the exact position permitted by the adjustable stop 128.

The control means for the latch members includes a cross bar 136 above which the hook portions 92 and 134 extend. Cross bar 136 is carried, in turn, by the vertically movable core 138 of a solenoid 140. Solenoid 140 is secured at 142 to a housing portion 144 carried by the latching plate 76. Wires 146 provide for convenient connection of the solenoid in circuit with motor 54 in known manner. In this particular embodiment of the invention, the solenoid 140 is connected in series with the motor, or in some other suitable circuit, to insure energiz'ation of the solenoid, while the motor 54 is operating to rotate the barrel assembly during the cooking phase of the operation.

When the cooking phase is terminated, the motor 54 is stopped and the solenoid 140 is simultaneously de-energized. Springs 88 and 106 then urge the latch members 72 and 98 toward locking position. To provide shockless or bounceless lift of the rebound latch face 98 over index stop 68, the index stop is associated with a cam lift portion 148 (Figs. 3, 4, and 5). Thus the parts will initially assume the position of Fig. 6, as the gun barrel assembly rotates toward its locking position of Fig. 7. Cam148 engages-a projection 150 (Fig. 4) on rebound latch 96 to hold the latch in the position of Fig. 6 until the index stop 68 has passed beneath the end 98 of the rebound latch. The parts can then drop into the position of Fig. 7. "It will be understood that the position of the parts shown in Figs. 3 and 6 will in actual operation correspond exactly to the positions they would assume while the latch support member is in the heavy line position of Fig. 2. The parts will then assume the position of Fig. 7, when the mechanism is first locked in the heavy line position of Fig. 2, and will retain this relative position during the further limited movement of the latching mechanism from the heavy line to the dotted line position of Fig. 2 and then back to the heavy line position again. During subsequent operation of the gun assembly, the energization of motor 54 will be accompanied by energization of solenoid 148 to lift the latch members from the position of Fig. 7 back to the position of Fig. 3 and again permit free rotation of the barrel assembly.

A preferred embodiment of the invention is shown in Figs. 8 and 9 in which the mass of the moving parts of the indexing and latching mechanism is substantially reduced. In this embodiment of the invention the indexing ring 166 is secured to gear 60 and is provided with a recess in its circumferential surface throughout a region indicated at 168. At one end of this recess 168 is a locking shoulder 1'70 adapted for engagement by the end 172 of the indexing or latch member 173. This latching member is pivoted at 174 to a latch-support member 176. The latter in turn is rigidly secured to a hub 178 rotatably mounted by means of bushing 180 on the hub 82 of main driving gear 60 of the gun barrel assembly. The other end 184 of the latching member carries a roller 186 adapted to provide a control surface for operation of the latch as described below. The spring 188 has one end connected to the end 184 of the latching member and has its other end secured at 190 to a suitable lug on a cross arm 192. Cross arm 192 is an extended part of the latching member 176 (Fig. 9). Pins 174 serve as pivots for the latch members.

A rebound latch 196 is pivoted at 194 on the support member 176. The effective end 198 of the rebound latch 196 is adapted to engage a shoulder 200 at the other end of the recess 168 on indexing ring 166. The opposite end 282 of the rebound latch 196 carries a roller 204 adapted to provide a control surface. A spring 206 (Fig. 9) is connected between the end 282 of lever 196 and a suitable lug on the latching plate 176. Thus springs 188 and 206 tend to urge the latching portions 172 and 198 against the indexing ring and into engagement with their respective locking surfaces 170 and 200. At this same time the springs tend to urge control rollers 186 and 204 radially outwardly from the axis of rotation of the gun barrel assembly.

To limit the relative rotation of the latch support member and its associated parts, a shock-absorbing unit is connected at 208 to the cross arm 192. The shock-absorber assembly again includes a spring 210 having its other end connected at 212 to a bracket 214 on frame 14. Similarly a piston rod and cylinder assembly is also connected between the supporting plate and frame. Thus the piston rod 216 has one end connected at 208 and its other end connected to a piston within cylinder 220. The cylinder in turn is secured at 222 to a bracket 224 on the frame. In this respect the parts may be essentially identical to those of the previous embodiment of the invention in Figs. 1 through 7.

To control the movement of latch members 173 and 196 between their locking and releasing positions, a movable control member 234 is supported on the frame for movement between first and second positions. When the latch members are in the releasing position of Fig. 8 the control projections or rollers 186 and 204 would describe an arcuate path during any limited relative rotation of the latching support on the frame. To hold the rollers in this path, the control member 234 includes an arcuate surface 236 which in the heavy line position of Fig. 8 establishes the desired path or locus for these control rollers. When it is desired to move the latching memhers into locking position so that they will engage the shoulders and 200, the control member 234 must be retracted to the dotted line position of Fig. 8. This will permit the springs 188 and 2 96 to urge the rollers to new positions located radially outwardly from the heavy line positions of Fig. 8. In these new positions relative rotation of the latch support would move the rollers in a second arcuate path parallel to but of greater radius than the path defined by the heavy line position of the control member surface 236.

A spring 238 is connected at one end to the control member 234 and at the other end to a suitable bracket on the frame member 240. Thus the spring normally urges the control member toward the dotted line position of Fig. 8 to permit locking engagement of levers 173 and 196 with the indexing ring 166.

To hold the parts in the releasing position shown in heavy lines in Fig. 8, the control member 234 is connected to a suitable solenoid. For this purpose the memher is supported by a lever arm 242 (Fig. 9) pivoted at 244 to frame 240. Lever arm 242 may constitute part of a bell crank which includes a vertical arm 246. Arm 246 has its upper end connected by a link 248 to the horizontally movable core 250 of a solenoid 252. Solenoid 252 is secured to a housing portion 254 of frame 240 and is provided with Wires 256 for connection in the motor circuit.

In this embodiment of the invention, energization of the solenoid will hold the arcuate control surface 236 in the heavy line position of Fig. 8 and will thus retain the latched members in releasing position during normal operation of the pufiing gun. The solenoid may be connected in circuit so that de-energization of the driving motor for the putting gun assembly will be accompanied by de-energization of solenoid 252. Spring 238 will then retract the control member 234 and permit the springs 188 and 206 to move the latching members into locking position.

When the latch members engage surfaces 176 and 200 the putfing gun barrel assembly Will be effectively locked to the latch support assembly and will tend to rotate the latch support member in the continuing direction shown by the arrow. While limited rotation of the parts in this direction is possible, such rotation will be resisted by the shock-absorbing assembly including spring 210, and the piston 218 and cylinder 220.

When movement of the parts is arrested, the spring 210 will urge the puffing gun assembly and latch member back toward the heavy line position of Fig. 8. Thus the parts will be urged to the desired predetermined angular position defined by the adjustable stop means. This adjustable stop means is identical to that shown in previous embodiment and includes a stop surface 226 on one end of the cross arm 192 of member 176. This surface engages the head 228 of an adjustable bolt which is threaded into a frame portion 30. Lock nut 232 again retains the parts in the desired adjusted position and permits further adjustment as needed for accurate determination of the locking position of the parts.

According to the foregoing description, an improved pufiing gun indexing mechanism has been described which substantially accomplishes the objects set forth at the beginning of the specification. Since minor variations and changes in the exact details of construction will be apparent to persons skilled in this field, it is intended that this invention shall cover all such changes and modifications as fall Within the spirit and scope of the foregoing description and the attached claims.

Now therefore we claim:

1. In a pufling gun having a frame, a gun barrel assembly rotatably mounted thereon, and a latch member movable between a locking position in which it engages a portion of said assembly to lock the assembly in a predetermined angular position and a releasing position in which the assembly is free to rotate, the improvement comprising means supporting said latch member for limited additional movement with the'assembly in the normal direction of rotation of said assembly after said latch engages and locks the assembly, and shock absorbing means resisting said limited additional movement of the latch member and thereby gradually stopping rotation of said assembly.

2. A pulling gun according to claim 1 in which said shock absorbing means includes means urging return movement of the latch and barrel assembly back to said predetermined angular position after said rotary movement has stopped.

3. A pufling gun according to claim 2 including stop means limiting the return movement of the latch and barrel assembly, and means for adjusting the effective angular position of said stop means and thereby adjusting said predetermined angular position.

4. A pufiing gun according to claim 1 in which said latch supporting means includes a support member mounted for rotation coaxially with said assembly.

5. A puffing gun according to claim 4 in which said shock absorbing means includes a spring connected between said support member and frame.

6. A pufimg gun according to claim 5 in which said spring is connected under tension to resist said additional movement and cause said return movement and in which said shock absorbing means also includes a damping cylinder and piston assembly connected between said plate and frame.

7. A puffing gun according to claim 1 in which said latch supporting means includes a support member mounted for rotation coaxially with said assembly to provide for said limited additional movement, said latch member being movably mounted on the support and having a projecting control surface adapted to follow a first arcuate path when the support member rotates and the latch is in locking position and a second arcuate path when the support member rotates and the latch is in releasing position, an arcuate control member mounted on said frame for movement between a first position in which it engages the control surface and holds said control suris face -in'one of said paths throughout the limited rotation of said support member and a'second position in which the control surface follows the other of said paths throughout such rotation, and motor means on said frame selectively moving said control member from one of said positions to the other.

8. A puffing gun according to claim 1 in which said latch supporting means includes a plate member generally perpendicular to the axis of rotation of the assembly, and means supporting said plate for rotation on said axis, said shock absorbing means including a spring connected between said plate and said frame.

9. A pufling gun having a frame, a gun barrel assembly rotatably mounted on said frame and including a barrel, a removable cover for the barrel and releasable locking means securing the cover to the barrel and r0- tating with the barrel, releasing means for said locking means mounted on the frame and movable to release said locking means only when the locking means and gun barrel are rotated to one predetermined angular position, an indexing latch movable between locking andi'f releasing positions, means on said gun barrel assembly adapted for engagement by said latch to lock the barrel in said predetermined angular position, means supporting said latch for limited additional movement with the assembly in the normal direction of rotation of the barrel beyond said position, and shock absorbing means operatively associated with said latch and opposing said additional movement to gradually stop the rotary movement of said barrel, said shock absorbing means including means urging return movement of said latch and barrel assembly back to said predetermined angular position after said rotary movement has stopped.

10. A pufling gun assembly according to claim 9 having adjustable stop means limiting the return movement of the latch and barrel assembly and thereby providing means for selective adjustment of said predetermined angular position to insure effective operation of said releasing means.

No references cited. 

